I changed fuel pump and relay on a 1997 gmc ,still no start.What do i check next?

Question

It now sounds like its getting allittle gas but still wont run.

Answer 1

On that particular year truck, you have to have at least 50 psi of fuel pressure before the engine will start. They have a strange set up for the fuel injectors. The injectors are turned on by the computer, but they have pop off valves at the end of the tubes that attach to the inside of the intake manifold. If you have good fuel pressure, then you must have another type of problem. You need to check to see if the engine is getting any spark to the spark plug wires. If you have no spark it could be a coil, distributor cap and rotor, coil wire,etc.
Good luck!

Answer 2

Check if you are getting any spark to the plugs, if you are, change the spark plugs, and it would be a good idea to change the cap and rotor. If there is no spark to the plugs, its the ign. module. but more than likely its the cap/rotor and spark plugs. I'm gonna guess you live up here in the northeast or close by. I have had lots of customers, with your same problem. Check those items, and let me know......ps, take the dist. cap off, and look at the inside of it. If it has some whiteish corrosion, that's your problem.

Answer 3

It probably wasn't the fuel pump. It could be the starter, the alternator, or the battery. Take it to a shop and let them look at it. Most won't charge just to take a look and see which is the problem.

Answer 4

If its getting gas, then i would check for spark by pulling out the #1 spark plug and setting it by the plug hole ..but dont touch..have an assistant turn over the engine if you dont see spark check the coil ecm or pcm.

Answer 5

is it getting good spark? have you checked the fuel pressure? You should have atleast 35psi for it to run correctly


p.s if it was the batt or the starter it would not even turn the engine over

Answer 6

turn the ignition key

Answer 7

model and engine???